Your start, measured.
You upload your start. SwimVolt tracks it frame by frame and shows you exactly what to work on.
01 — How it works
Three steps, about a minute.
No tripod, no sensors, no coach standing over you. A phone on the pool deck is the whole setup.
Step 1: Film one dive
Scroll on to watch step 2 happen
02 — See it in action
Scroll the dive.
Watch it get measured.
The film holds still at the frames a measurement is taken at, so you can see the mark land on a body that isn't moving under it. A real start, restaged — the same measurement pass your clip gets.
03 — What we measure
41 measurements, one dive.
Three from each phase, read off one real dive.
Back heel · setup
30°
How high your back heel is off the block at the set position.
Back heel: 30° setup. How high your back heel is off the block at the set position.
04 — The literature
SwimVolt names the paper behind every range.
Targets come from published swimming biomechanics, from coaches, or from our own estimate — and each one says which it is.
- 2021Matúš et al. (2021)Int. Journal of Environmental Research and Public Health
Set-position knee angles and entry angle in competitive swimmers. Our front-knee range started here at 125-140°; the ceiling is now 160°, raised by coaching after every reference swimmer measured above it.
18 male competitive swimmers, 50 m freestyle 23.3 s
- 2020van Dijk et al. (2020)PLoS ONE
Entry angle across 349 starts, corroborating the range above independently. The band we use is now the coaching one and slightly shallower at 30-40°.
14 sub-elite and elite swimmers, 349 starts
- 2021Shepherd et al. (2021)Sports Biomechanics
Which parts of a start actually predict a fast time — trunk position matters, individual limb angles at takeoff do not.
24 elite swimmers (12 men, 12 women)
- 2026Born et al. (2026)Bioengineering
The take-off speed comparison range. Not a target — even its slowest swimmers are national-team level, so it shows where a number sits rather than grading it.
136 national-team swimmers, including Olympic medallists and a world-record holder
Also Matúš (2020), Slawson (2012), Tor (2017). Full sources. The coaching rules came from coaches and biomechanists, and from swimming the event ourselves. We refilmed the same starts to check ourselves and published what we found.
05 — Behind the software
Built by a swimmer.
Christopher Zhang
Founder
Christopher Zhang is a current D1 swimmer at Brown University.
“Starts are one of the hardest things in swimming to learn. I wanted to build software for a problem I actually had, and make starts easier for everyone.”
06 — Re-analyze & track change
Film it again next week.
SwimVolt counts how many times you repeat the same fault. Every dive stays in your log with its pose replay.
See an example dive logYour repeating fault
You missed your hand pull-back in 4 of your last 5 dives.
last 5 sessions · fault present · example
Pricing
Two analyses a month, free, at full depth. Go unlimited when you want more.
Free
Try it on a few dives
- 2 analyses every month, at full depth
- Saved history with pose-overlay replays
- Your footage stays yours. Delete it anytime.
Athlete
Analyze every dive you film
billed $29.99 / year
- Unlimited analyses
- Everything in Free
- Cancel anytime
Coaches
For clubs and school programs
- The same start analysis your swimmers use today
- Club tools (rosters, comparison, batch) are not in the app yet
No dashboards to buy. If you coach a squad, tell us what you need and we'll say honestly what's next.
Questions, answered
What do I need to film?
One clip, 10 seconds or less, landscape, filmed from the side of the pool so the whole dive is visible. Any phone works and you don't need a tripod. SwimVolt measures camera shake and flags the clip if it moved too much to trust.
How accurate are the numbers?
The same clip gives you the same measurements every time, each one read at its own frame. We refilmed the same dives to check ourselves, and some angles flip between takes. That's why we count how many times a fault repeats.
Does AI make up the numbers?
No — there is no AI anywhere in the analysis. Every measurement, every correction and every line of praise is computed from the tracked frames, so the same clip gives you the same answer every time. An AI used to write the commentary on top of the numbers; it was taken out.
Won't the same dive measure differently from a different angle?
Some of it will, and we measured how much. We filmed the same dives with two cameras at once and compared. Trunk angles, timings and distances barely move — forward lean shifts about 1.7°, entry angle about 2.2°. Angles at your knees, hips and head move a lot more, because from the side your near leg hides your far one. That's why those are shown for reference and the coaching leans on the measurements that hold still. If your camera isn't square to the lane we detect it from your left and right sides measuring different lengths, and the result says so.
Where do the target ranges come from?
Targets come from published swimming biomechanics wherever that exists. Where it doesn't, we label the number our own estimate. Every target names its source in the app.
What happens to my footage?
It's stored under your account so you can rewatch analyzed dives with the pose overlay. Delete a dive, or your whole account, anytime, and the video is actually gone from storage.
Does it work for strokes?
Not yet. SwimVolt only measures the dive start for now: setup, launch, flight, entry. Strokes are on the roadmap.
Get on the clock.
One clip. The whole start, measured.